Question for avstream event and method handler

hello, everybody:
I have designed a avstream mini-driver, it works good, Now, we want to add some methods and events in order to get compressed video data from video capture card(at the same time, doing video real-time display, but the data frame displayed not the compressed video data). although i have read ddk, i’m not very clear, so can anybody tell me how to implement?

thanks very much

mark chen